High speed line laser based scalable variable spot size light solidification additive manufacturing apparatus and control method

Abstract

The application is a high-speed line laser-based expandable variable spot light-curing additive manufacturing device and control method, which comprises an optical engine, an X-direction moving module, a Y-direction moving module, a Z-direction moving module, a printing platform, a scraper, a material cylinder, a rack, a partition, a point laser scanner and a control center; the optical engine is arranged above the printing platform and connected with the X-direction moving module; the printing platform is connected with the Z-direction moving module; the scraper is installed above the printing platform; the X-direction moving module is installed in the X-direction guide rail of the partition; the Y-direction moving module is installed in the Y-direction guide rail of the partition; the Z-direction moving module is installed at the rear of the rack; the material cylinder is placed below the partition; and the point laser scanner is installed on the upper part of the rack. By selecting the printing mode of line spot scanning, the printing speed can be appropriately accelerated under the premise of fully ensuring the printing quality.

Description

Technical Field

[0001] This invention relates to the field of 3D printing technology, and in particular to a photopolymerization additive manufacturing apparatus and control method based on a high-speed linear laser with an expandable and variable spot size. Background Technology

[0002] Photopolymerization is the earliest and most mature 3D printing technology. This technology utilizes material stacking to create a model by dividing the target model into several planar layers. A light beam of a specific wavelength scans liquid photosensitive resin; the scanned resin solidifies, while the unscanned resin remains liquid. As layers are stacked, the desired target model is eventually obtained. This technology is now used in various fields such as aerospace and automotive manufacturing.

[0003] Currently, the mainstream photopolymer 3D printing technologies mainly consist of two techniques: stereolithography (SLA) and digital light processing (DLP). Stereolithography (SLA) involves a point-by-point scanning printing method. Each deflection of the galvanometer completes the printing of only one point. Points are connected to form lines, and lines to form surfaces. As layers of material are stacked, the target model is finally obtained. However, due to the point-by-point scanning method, this technology becomes drastically time-consuming when printing large areas, making it inefficient for large-scale printing. Digital light processing (DLP) technology involves surface exposure printing, which can form one surface at a time, offering high efficiency. However, it is limited by the number of pixels in the optical engine, leading to decreased accuracy in large-format printing and making it unsuitable for large-scale model production. Both stereolithography (SLA) and DLP technologies have their advantages, but neither can simultaneously achieve optimal printing performance in large-scale photopolymer printing. LSU printing technology balances accuracy and efficiency, but this drawback becomes increasingly apparent as the printing size increases, hindering the further promotion of photopolymer 3D printing. Therefore, there is an urgent need for a high-quality printing device that can meet the printing needs of various large-size models and balance printing efficiency and accuracy during use. Summary of the Invention

[0004] To address the technical problems existing in the prior art, this invention provides a photopolymerization additive manufacturing device and control method based on a high-speed linear laser with an expandable and variable spot size. By selecting a linear spot scanning printing method, the printing speed can be appropriately increased while ensuring printing quality.

[0005] The device of this invention is implemented using the following technical solution: a photopolymerization additive manufacturing device based on high-speed linear laser with expandable and variable spot, including an optical engine, an X-direction moving module, a Y-direction moving module, a Z-direction moving module, a printing platform, a scraper, a material cylinder, a frame, a partition, a point laser scanner, and a control center;

[0006] The optical engine is positioned above the printing platform and connected to the X-direction moving module, allowing it to reciprocate linearly along the X-direction under the drive of the X-direction moving module.

[0007] The printing platform is connected to the Z-direction moving module, which drives the printing platform to reciprocate linearly along the Z-direction inside the material cylinder.

[0008] The scraper is installed above the printing platform and, driven by the Y-direction moving module, completes the spreading of material on the printing platform;

[0009] The X-direction movement module is installed inside the X-direction guide rail of the partition;

[0010] The Y-direction moving module is installed inside the Y-direction guide rail of the partition;

[0011] The Z-direction movement module is installed at the rear of the rack;

[0012] The material cylinder is placed below the partition, and the printing platform moves linearly inside the material cylinder to adhere the printing material.

[0013] The point laser scanner is installed on the upper part of the frame and performs secondary scanning and solidification on the overlapping area of ​​the linear light spots of the two sets of optical engines in the X direction and the boundary area of ​​the overlapping area of ​​the linear light spots in the Y direction using point lasers.

[0014] The control center is interconnected and communicates with the optical engine, the X-axis movement module, the Y-axis movement module, the Z-axis movement module, and the point laser scanner.

[0015] The control method of this invention is implemented using the following technical solution: a control method for a photopolymerization additive manufacturing device based on a high-speed linear laser with an expandable and variable spot size, comprising the following steps:

[0016] S1. Obtain the print model;

[0017] S2. Import the printed model into the slicing software. Based on the size of the laser spot of the optical engine laser, identify the contour, fine structure, laser overlap, laser overlap and other feature dimensions, and divide the relevant areas for scanning of large and small spots.

[0018] S3. Obtain the slice file containing the laser scanning path and import it into the device for printing;

[0019] S4. Use the Z-direction moving module to raise the printing platform until the upper surface of the printing platform is at the same height as the upper surface of the partition.

[0020] S5. Fill the material cylinder with printing material until the material level just covers the printing platform;

[0021] S6. Use the Y-direction moving module to drive the scraper to spread the material evenly on the upper surface of the printing platform;

[0022] S7. Import the slice file and start printing;

[0023] S8. Control the X-axis linear motion module to drive the two sets of optical engines to move towards each other, and turn on the large spot laser I to scan. The two sets of optical engines move from both ends to the middle along the X direction. When the large spot filling is finished, turn off the large spot laser I.

[0024] S9. Simultaneously turn on the small spot laser II and the point laser scanner, control the X-direction movement module to drive the two sets of optical engines to move in opposite directions, and turn on the small spot laser II to scan. The two sets of optical engines move from the middle to both ends along the X direction. After the small spot filling is completed, turn off the small spot laser II. After the point laser scanner is turned on, it will perform a second scan and solidify the overlapping part of the linear spot X direction of the two sets of optical engines in the middle and the junction of the linear spot Y direction optical engines. After the scan is completed, turn off the point laser scanner. The solidification light source will solidify the material, thereby completing the printing of one layer.

[0025] S10. The Z-direction moving module drives the printing platform to descend by one printing layer thickness, and the Y-direction moving module drives the scraper to spread the material evenly on the upper surface of the printing platform.

[0026] S11, control the X-direction movement module, large spot laser I, small spot laser II and point laser scanner, repeat steps S8 and S9, the laser solidifies the new layer of material, and the printing of the new layer is completed;

[0027] S12. The Z-direction moving module is used to drive the printing substrate to descend by another printing layer thickness, and the Y-direction moving module continues to drive the squeegee to spread the material evenly on the upper surface of the printing platform.

[0028] S13. Repeat steps S8 to S12 until the entire model is printed.

[0029] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0030] 1. This invention balances printing accuracy and efficiency. Existing mainstream photopolymer 3D printing technologies include Digital Light Processing (DLP) and Stereolithography (SLA). For large-size printing, DLP is limited by the number of optical engine pixels, resulting in low printing accuracy. SLA, with its point-to-point scanning method, suffers from low printing efficiency, hindering the advancement of photopolymer 3D printing to larger sizes. This invention utilizes a line-spot scanning printing method, combining the advantages of both technologies to appropriately increase printing speed while maintaining print quality. To further improve efficiency, this invention proposes a variable-spot alternating scanning printing method. Two lasers are installed inside the optical engine, emitting small and large diameter laser spots respectively. The optical engine moves in opposite directions by controlling the forward and reverse rotation of the motor. During the forward movement, the large spot fills the large printing area, while during the reverse movement, a small spot outlines small printing details, further improving printing efficiency while maintaining accuracy.

[0031] 2. This invention is suitable for large-size printing. As additive manufacturing trends towards larger and more integrated models, equipment must be able to meet the printing needs of large-format models. Traditional methods for printing large-size models involve dividing the model into several parts, fabricating each part, and then assembling them. This results in low precision at the model joints, a cumbersome manufacturing process, and high processing and labor costs. The line spot overlapping method proposed in this invention can multiply the width of the line spot emitted by a single optical engine by connecting multiple optical engines in series. The optical engine housing is designed with clips for direct connection to another optical engine. The optical engine mounting block uses a gantry structure, allowing for flexible disassembly during overlapping. To ensure the curing quality of the line spot overlapping area, this invention also incorporates a point laser scanner for secondary scanning and curing of the overlapping area, further guaranteeing the structural strength of the overlapping area.

[0032] 3. This invention has high scalability and flexibility. By using a linear spot overlapping method, multiple optical engines can be connected in series in the Y direction, which multiplies the scanning width of the linear spot. In the X direction, the scanning distance of the linear spot can be continuously increased by extending the track and increasing the scanning length of the optical engine. Through the increase of the scanning distance in the X direction and the expansion of the scanning width of the linear spot in the Y direction, the printing size allowed by the device can be further increased. According to the actual printing needs, the appropriate scanning distance and the number of optical engines connected in series can be selected to complete the printing of larger-sized models, which has high scalability. While expanding the printing area, multiple point laser scanners can be used to divide different printing areas. Each point laser scanner performs a secondary scan and solidifies the overlapping area of ​​the linear spot in the X direction of the two sets of optical engines and the overlapping area of ​​the linear spot in the Y direction in its respective area, making the printing size of the device more flexible and able to simultaneously meet the printing requirements of size, efficiency and accuracy. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the structure of the device of the present invention;

[0034] Figure 2 This is a schematic diagram of a variable spot optical engine;

[0035] Figure 3 These are schematic diagrams of large and small spot lasers;

[0036] Figure 4 This is a schematic diagram of the optical engine connection;

[0037] Figure 5 This is a schematic diagram of the overlapping area of ​​the linear light spot in the X direction;

[0038] Figure 6 This is a schematic diagram of the overlap of linear light spots in the Y direction;

[0039] Figure 7 This is a magnified schematic diagram of the overlapping of linear light spots in the Y direction;

[0040] Figure 8 This is a flowchart of the control method of the present invention;

[0041] In the diagram, 1 is the optical engine, 2 is the X-axis movement module, 3 is the Y-axis movement module, 4 is the Z-axis movement module, 5 is the printing platform, 6 is the scraper, 7 is the material cylinder, 8 is the frame, 9 is the partition, 10 is the point laser scanner, 11 is the control center, 12 is the L-shaped support rod, 101 is the large spot laser I, 102 is the small spot laser II, 103 is the concave mirror, 104 is the multi-faceted rotating mirror, 105 is the reflector, 106 is the outer shell, and 1061 is the buckle. Detailed Implementation

[0042] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0043] Example

[0044] like Figure 1 As shown, this embodiment of a photopolymer additive manufacturing apparatus based on a high-speed linear laser with scalable and variable spot size includes an optical engine 1, an X-axis moving module 2, a Y-axis moving module 3, a Z-axis moving module 4, a printing platform 5, a scraper 6, a material cylinder 7, a frame 8, a partition 9, a point laser scanner 10, and a control center 11. The optical engine is positioned above the printing platform and connected to the X-axis moving module, causing it to reciprocate linearly along the X-axis under the drive of the X-axis moving module. The printing platform is connected to the Z-axis moving module, causing it to reciprocate linearly along the Z-axis inside the material cylinder under the drive of the Z-axis moving module. The scraper is mounted on the printing platform. Above, driven by the Y-direction moving module, the printing platform completes the material application; the X-direction moving module is installed in the X-direction guide rail of the partition; the Y-direction moving module is installed in the Y-direction guide rail of the partition; the Z-direction moving module is installed at the rear of the frame; the material cylinder is placed below the partition, and the printing platform moves linearly within the material cylinder to adhere the printing material; the point laser scanner is installed on the upper part of the frame, and performs secondary scanning and curing on the overlapping area of ​​the linear spot X-direction of the two sets of optical engines and the overlapping boundary area of ​​the linear spot Y-direction through point laser; the control center is interconnected and communicates with the optical engine, the X-direction moving module, the Y-direction moving module, the Z-direction moving module, and the point laser scanner.

[0045] like Figure 2 As shown, in this embodiment, the optical engine includes a large-spot laser I 101, a small-spot laser II 102, a concave mirror 103, a multi-faceted rotating mirror 104, a reflector 105, and a housing 106. The large-spot laser I and the small-spot laser II are stacked and placed in the lower middle part of the housing. The multi-faceted rotating mirror is installed in the upper part directly in front of the large-spot laser I and the small-spot laser II. The reflector is located in the upper rear part of the laser, and the concave mirror is located in the upper part of the middle position between the laser and the multi-faceted rotating mirror. The large-spot laser I and the small-spot laser II emit point-shaped light spots. After passing through the high-speed rotating multi-faceted rotating mirror, the point-shaped light spots are transformed into line-shaped light spots and reflected onto the rear reflector. The reflector then reflects the light spots onto the concave mirror for optical path compensation, ultimately ejecting the line-shaped light spots from the housing.

[0046] like Figure 4As shown, specifically in this embodiment, a buckle 1061 is designed on the housing of the optical engine. Multiple optical engines are connected in parallel through the buckle to complete the overlap of linear light spots in the Y direction, thereby achieving a multiple expansion of the scanning width of the linear light spots in the Y direction. At the same time, the point laser scanner performs point-by-point secondary scanning and solidification on the junction area of ​​the two linear light spots of the two optical engines in the Y direction to ensure the printing quality at the overlap.

[0047] Specifically, large-spot laser I and small-spot laser II use lasers with different spot diameters. Large-spot laser I and small-spot laser II operate alternately. The emitted laser light passes through a high-speed, unidirectional rotating multifaceted mirror, forming a linear spot, which is then reflected onto a concave mirror. After further reflection by the concave mirror, it is reflected by a reflecting mirror, which then emits the linear spot. Figure 3 As shown, large spot laser I uses a large spot laser to fill the printing area by scanning with a large spot, thus improving printing efficiency; small spot laser II uses a small spot laser to print fine structures by outlining with a small spot, thus ensuring printing accuracy. The two lasers are turned on and off alternately, balancing printing efficiency and printing accuracy. The outer shell is designed by Solidorks computer-aided design and integrally formed by FDM additive manufacturing.

[0048] In this embodiment, the X-direction movement module controls the forward and reverse rotation of the drive motor to drive the optical engine in both directions, ultimately enabling the two sets of optical engines to move relative to each other or in opposite directions simultaneously. The control center controls the large spot laser I and the small spot laser II. When the two sets of optical engines move towards each other or in opposite directions, the large spot laser I and the small spot laser II are activated respectively, using laser spots of different diameters for scanning. The point laser will perform a secondary scan and solidify the overlapping area of ​​the linear spots of the two sets of optical engines in the X direction. By alternating scanning of large and small spots with secondary scanning of the point laser, excellent printing accuracy can be achieved while maintaining printing efficiency.

[0049] In this embodiment, the Y-direction movement module achieves bidirectional material application by controlling the forward and reverse rotation of the drive motor. In this embodiment, the Z-direction movement module is fixedly connected to two L-shaped support rods, and driven by the drive motor, it propels the printing platform to move linearly along the Z-direction.

[0050] In this embodiment, the control center controls the activation and deactivation of the large-spot laser I and the small-spot laser II. Specifically, when the two optical engines move towards each other, the large-spot laser I is activated and the small-spot laser II is deactivated, allowing for scanning with the large spot. When the two optical engines move from both ends to the center, the drive motor stops, the optical engines stop moving, and the large-spot laser I is deactivated. The drive motor then reverses direction, and when the two optical engines move away from each other, the small-spot laser II is activated, allowing for scanning with the small spot. When the two optical engines move from the center to both ends, the drive motor stops, the optical engines stop moving, and the small-spot laser II is deactivated, completing the curing of one layer of material. Using laser spots of different sizes for scanning, with a large spot improving printing efficiency and a small spot ensuring printing quality, the alternating scanning method of large and small spots significantly improves printing efficiency while maintaining printing accuracy in large-size printing.

[0051] like Figure 5 , Figure 6 , Figure 7 As shown in this embodiment, when multiple optical engines are overlapped, the number and installation position of the point laser scanners can be adjusted according to the change in the number of overlapping optical engines. When printing in large format, multiple point laser scanners can be used to divide different areas to perform secondary scanning and solidification on the overlapping area of ​​the linear spot X direction of the two sets of optical engines and the overlapping boundary area of ​​the linear spot Y direction, so as to achieve both printing accuracy and printing efficiency.

[0052] like Figure 8 As shown, this invention also proposes a control method for a photopolymerization additive manufacturing apparatus based on a high-speed linear laser with an scalable and variable spot size, comprising the following steps:

[0053] S1. Obtain the print model;

[0054] S2. Import the printed model into the slicing software. Based on the size of the laser spot of the optical engine laser, identify the contour, fine structure, laser overlap, laser overlap and other feature dimensions, and divide the relevant areas for scanning of large and small spots.

[0055] S3. Obtain the slice file containing the laser scanning path and import it into the device for printing;

[0056] S4. Use the Z-direction moving module to raise the printing platform until the upper surface of the printing platform is at the same height as the upper surface of the partition.

[0057] S5. Fill the material cylinder with printing material until the material level just covers the printing platform;

[0058] S6. Use the Y-direction moving module to drive the scraper to spread the material evenly on the upper surface of the printing platform;

[0059] S7. Import the slice file and start printing;

[0060] S8. Control the X-axis linear motion module to drive the two sets of optical engines to move towards each other, and turn on the large spot laser I to scan. The two sets of optical engines move from both ends to the middle along the X direction. When the large spot filling is finished, turn off the large spot laser I.

[0061] S9. Simultaneously turn on the small spot laser II and the point laser scanner, control the X-direction movement module to drive the two sets of optical engines to move in opposite directions, and turn on the small spot laser II to scan. The two sets of optical engines move from the middle to both ends along the X direction. After the small spot filling is completed, turn off the small spot laser II. After the point laser scanner is turned on, it will perform a second scan and solidify the overlapping part of the linear spot X direction of the two sets of optical engines in the middle and the junction of the linear spot Y direction optical engines. After the scan is completed, turn off the point laser scanner. The solidification light source will solidify the material, thereby completing the printing of one layer.

[0062] S10. The Z-direction moving module drives the printing platform to descend by one printing layer thickness, and the Y-direction moving module drives the scraper to spread the material evenly on the upper surface of the printing platform.

[0063] S11, control the X-direction movement module, large spot laser I, small spot laser II and point laser scanner, repeat steps S8 and S9, the laser solidifies the new layer of material, and the printing of the new layer is completed;

[0064] S12. The Z-direction moving module is used to drive the printing substrate to descend by another printing layer thickness, and the Y-direction moving module continues to drive the squeegee to spread the material evenly on the upper surface of the printing platform.

[0065] S13. Repeat steps S8 to S12 until the entire model is printed.

[0066] Specifically, in this embodiment, the division of the scanning area in step S2 is determined according to the spot size of the large spot laser I and the small spot laser II selected in the optical engine. In this embodiment, the diameter of the large spot is selected to be 700nm and the diameter of the small spot is selected to be 100nm. The fine structure and outline that need to be outlined by the small spot and the large-format filling area printed by the large spot are determined in the model slice layer, and the scanning path of the optical engine is obtained from this. In addition, it is necessary to determine the overlapping and coincident areas where the point laser scanner is to be solidified for the second time, and to determine the scanning path of the point laser scanner. Specifically, the point-to-line stage generated by the multi-faceted rotating mirror in the Y direction, the line-to-surface stage generated by the X-direction moving module in the X direction, and the point laser stage generated by the galvanometer in the X and Y directions are all determined.

[0067] Specifically, in this embodiment, the two sets of optical engines in steps S8 and S9 utilize the forward and reverse rotation of the drive motor to achieve flexible switching between opposing and reversing movements in the X direction. When printing begins, the forward rotation of the drive motor causes the two sets of optical engines to begin moving towards each other. At this time, both sets of optical engines activate the large spot of the large-spot laser I to scan, moving from both ends towards the middle. According to the laser scanning path, the large-format filling area that needs to be scanned by the large spot is solidified. After the two sets of optical engines have completed their respective areas that need to be solidified and reached the middle, the drive motor stops rotating, the large-spot laser I is turned off, and the drive motor starts to reverse, causing the two sets of optical engines to begin moving towards each other. At this time, both sets of optical engines activate the small spot of the small-spot laser II to scan, moving from the middle towards both ends respectively. According to the laser scanning path, the fine structure and contour that need to be printed by the small spot are solidified. After the two sets of optical engines have completed their respective areas that need to be solidified and reached both ends, the drive motor stops rotating, the small-spot laser II is turned off, and the printing of this layer ends.

[0068] Specifically, in this embodiment, the small-spot laser II and the point laser scanner in step S9 are turned on simultaneously. The point laser scanner will perform a secondary scan on the laser overlap area generated when the two sets of optical engines meet in the X direction and the overlapping area of ​​the linear spots when the optical engines are connected in series in the Y direction by scanning point by point. In the overlap area, the linear spots will affect the curing effect in the area due to the fluctuations in the movement of the two sets of optical engines. Similarly, at the overlapping point of the linear spots, the unavoidable vibration during printing causes fluctuations in the two linear spots, so the curing effect is more likely to occur at the junction. In cases of poor or even uncured material, a point laser scanner is used to perform a secondary scan and curing of overlapping and mating areas. This high-quality point-by-point scanning method ensures successful curing of the material in both overlapping and mating areas, guaranteeing printing accuracy and quality. The small-spot laser II and the point laser scanner work together according to the planned scanning path to complete the printing of the relevant areas in the shortest possible time, maximizing printing efficiency. In this embodiment, both the point laser scanner and the small-spot laser II use 100nm laser light sources with the same spot size, effectively ensuring the consistency and uniformity of the curing effect.

[0069] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A high speed line laser based scalable variable spot size light solidification additive manufacturing device characterized in that, The device comprises an optical engine, an X-direction moving module, a Y-direction moving module, a Z-direction moving module, a printing platform, a scraper, a material cylinder, a frame, a partition, a point laser scanner and a control center. The optical engine is arranged above the printing platform and connected with the X-direction moving module, so that the optical engine moves linearly along the X-direction under the drive of the X-direction moving module. The printing platform is connected with the Z-direction moving module, so that the printing platform moves linearly along the Z-direction under the drive of the Z-direction moving module. The scraper is installed above the printing platform and driven by the Y-direction moving module to complete the material paving of the printing platform. The X-direction moving module is installed in the X-direction guide rail of the partition. The Y-direction moving module is installed in the Y-direction guide rail of the partition. The Z-direction moving module is installed at the rear of the frame. The material cylinder is arranged below the partition, and the printing platform moves linearly in the material cylinder to stick and cover the printing material. The point laser scanner is installed on the upper part of the frame, and the point laser performs secondary scanning and solidification on the X-direction overlapping area of the two linear light spots of the optical engine and the Y-direction overlapping area of the linear light spots. The control center is connected with the optical engine, the X-direction moving module, the Y-direction moving module, the Z-direction moving module and the point laser scanner. The optical engine comprises a large-spot laser I, a small-spot laser II, a concave mirror, a multi-faceted mirror, a reflector and a shell. The large-spot laser I and the small-spot laser II are arranged in the lower part of the shell, the multi-faceted mirror is installed in the upper part in front of the large-spot laser I and the small-spot laser II, the reflector is arranged in the upper part behind the laser, and the concave mirror is arranged in the upper part between the laser and the multi-faceted mirror. The large-spot laser I and the small-spot laser II emit point light spots, which are changed into linear light spots by the high-speed rotating multi-faceted mirror, reflected to the reflector, reflected to the concave mirror by the reflector, compensated in the light path, and finally emitted out of the shell.

2. The high speed line laser based scalable variable spot size photo-curing additive manufacturing device of claim 1, wherein, The shell of the optical engine is designed with buckles, and multiple optical engines are connected in parallel through the buckles to complete the lapping of the linear light spots in the Y-direction.

3. The high speed line based laser scalable variable spot size photo-curing additive manufacturing apparatus of claim 1, wherein, The X-direction moving module drives the bidirectional linear movement of the optical engine by controlling the forward and reverse rotation of the driving motor, and finally realizes the relative movement or opposite movement of the two optical engines.

4. The control method of the scalable variable spot size, high speed line laser based, light solidification additive manufacturing apparatus of claim 1, wherein, The control center controls the large-spot laser I and the small-spot laser II, and the two optical engines open the large-spot laser I and the small-spot laser II respectively during the relative movement and opposite movement, and use laser spots of different diameters for scanning. The Y-direction moving module realizes the bidirectional material paving of the scraper by controlling the forward and reverse rotation of the driving motor. The Z-direction moving module is fixedly connected with two L-shaped supporting rods, and drives the printing platform to move linearly along the Z-direction under the drive of the driving motor. The device comprises the following steps: S1, obtaining a printing model; S2, importing the printing model into slicing software, identifying the contour, fine structure, laser overlap, laser coincidence and other area feature sizes according to the size of the optical engine laser spot, and dividing the related area of the large spot scanning; S3, obtaining a slicing file containing a laser scanning path, and importing the device for printing; S4, using the Z-direction moving module to drive the printing platform to rise until the upper surface of the printing platform is at the same height as the upper surface of the partition plate; S5, filling the material cylinder with printing material until the material level is just above the printing platform; S6, using the Y-direction moving module to drive the scraper to evenly spread the material on the upper surface of the printing platform; S7, importing the slicing file and starting printing; S8, controlling the X-axis linear motion module to drive the two groups of optical engines to move towards each other, and turning on the large spot laser I for scanning, the two groups of optical engines moving along the X direction from both ends to the middle, the large spot filling being completed, and the large spot laser I being turned off; S9, turning on the small spot laser II and the point laser scanner at the same time, controlling the X-direction moving module to drive the two groups of optical engines to move away from each other, and turning on the small spot laser II for scanning, the two groups of optical engines moving along the X direction from the middle to both ends, the small spot filling being completed, and the small spot laser II being turned off; the point laser scanner being turned on to perform secondary scanning and solidification on the X-direction coincidence of the two groups of optical engines in the middle and the Y-direction optical engine overlap junction of the linear spot, the scanning being completed and the point laser scanner being turned off, and the curing light source being used to solidify the material, thereby completing the printing of one layer; S10, using the Z-direction moving module to drive the printing platform to descend by one printing layer thickness, and using the Y-direction moving module to drive the scraper to evenly spread the material on the upper surface of the printing platform; S11, controlling the X-direction moving module, the large spot laser I, the small spot laser II and the point laser scanner to repeat steps S8 and S9, the laser solidifying the new layer of material to complete the printing of the new layer; S12, using the Z-direction moving module to drive the printing substrate to descend by one printing layer thickness, and using the Y-direction moving module to continue driving the scraper to evenly spread the material on the upper surface of the printing platform; S13, repeating steps S8-S12 until the entire model is printed. The two groups of optical engines in steps S8 and S9 realize flexible switching of the X-direction opposite movement and the X-direction opposite movement by using the forward rotation and the reverse rotation of the driving motor; when starting printing, the driving motor is rotated forward to make the two groups of optical engines start opposite movement, the two groups of optical engines are both opened to the large spot of the large spot laser I to perform scanning, and move from both ends to the middle, according to the laser scanning path, the large spot is scanned to solidify the large area filling region, after the two groups of optical engines respectively complete the region to be solidified, the driving motor stops rotating, the large spot laser I is closed, the driving motor is reversed to make the two groups of optical engines start opposite movement, the two groups of optical engines are both opened to the small spot of the small spot laser II to perform scanning, and move from the middle to both ends, according to the laser scanning path, the small spot is scanned to solidify the fine structure and the contour, after the two groups of optical engines respectively complete the region to be solidified, the driving motor stops rotating, the small spot laser II is closed, and the layer printing is completed.

5. The control method of a scalable variable spot size, high speed line laser based, light solidification additive manufacturing apparatus according to claim 4, characterized in that, The division of the scanning region in step S2 is determined according to the spot size of the large spot laser I and the small spot laser II selected in the optical engine; the fine structure, the contour and the large area filling region printed by the large spot laser I are determined in the model slice layer, the scanning path of the optical engine is obtained; the overlapping region and the lap region to be twice solidified by the point laser scanner are determined, the scanning path of the point laser scanner is determined, the Y-direction is generated by the point-to-line stage through the multi-surface rotating mirror, the X-direction is generated by the line-to-surface stage through the X-direction moving module, and the point laser stage is generated by the X and Y directions through the vibrating mirror piece.

6. The control method of a scalable variable spot size, high speed line laser based, light solidification additive manufacturing apparatus according to claim 4, wherein, The small spot laser II and the point laser scanner in step S9 are opened at the same time, the point laser scanner performs twice scanning on the laser overlapping region generated when the two groups of optical engines meet in the X direction and the lap region of the linear spot when the optical engines are connected in the Y direction by means of point-by-point scanning.

Images